From b8a008d86ae78c9b303f5df535dc016098be3ae1 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Fri, 28 Sep 2018 20:56:50 -0700
Subject: [PATCH] commit cc8b433532d9997081f1b9e7590ce8c90996e5be Author:
 Micha? Janiszewski <janisozaur+signed@gmail.com> Date:   Fri Sep 28 20:52:21
 2018 +0200

    PNM: Improve checks when loading a file
---
 IMG_pnm.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/IMG_pnm.c b/IMG_pnm.c
index 4c3707ec..35b66318 100644
--- a/IMG_pnm.c
+++ b/IMG_pnm.c
@@ -86,7 +86,14 @@ static int ReadNumber(SDL_RWops *src)
     } while ( SDL_isspace(ch) );
 
     /* Add up the number */
+    if (!SDL_isdigit(ch)) {
+        return -1;
+    }
     do {
+        /* Protect from possible overflow */
+        if (number >= INT32_MAX / 10) {
+            return -1;
+        }
         number *= 10;
         number += ch-'0';